Telomerization process for the preparation of allyl alcohol-,allyl acetate- and styrene-aldehyde reaction products



United States Patent US. Cl. 260-491 7 Claims ABSTRACT OF THE DISCLOSURE A taxogen selected from the group consisting of allyl alcohol, allyl acetate and styrene is telomerized with a lower alkanal, as telogen by reacting the telogen with the taxogen in the presence of nickel peroxide at a temperature from ambient temperature to the decomposition temperature of one of the telogen, the taxogen and their addition product, the said nickel peroxide being the product of the treatment of a salt of nickel selected from the group consisting of nickel chloride, nickel bromide, nickel sulfate, nickel carbonate and nickel nitrate with an oxidizing agent selected from the group consisting of alkali hypohalite and alkali persulfate in aqueous alkaline medium at a temperature between 10 and C., and containing about 0.3 to 0.4x 10- gram-atom of active oxygen per gram.

This application is a division of copending application Ser. No. 252,554, filed Jan. 12, 1963, now Patent No. 3,309,393, granted Mar. 14, 1967.

The present invention relates to a novel telomerization process wherein telogen is reacted with a taxogen in the presence of nickel peroxide to produce, as telomer, an allyl alcohol-aldehyde or allyl acetate-aldehyde or styrenealdehyde reaction product.

In the present specification, the term telomerization may be understood as the process of reacting under polymerization conditions, a molecule YX which is called a telogen with one or more than one unit of polymerizable compound having ethylenic unsauration called a taxogen to form products called telomers having the formula: Y(A) -Z, where (A) is a divalent radical formed by chemical union, with the formation of new carbon bonds of the taxogen, the unit A being called a taxomon, n being any integer greater than zero, and Y and Z being fragments of the telogen attached to both terminals of the taxomon or a chain of the taxomons, although the process wherein a telogen is reacted with only one unit of a taxogen to form a telomer having the formula: Y(A) Z is excluded from the category of telomerization in some text books [e.g., H. Gilman: Organic Chemistry, An Advanced Treatise, volume IV, pp. l043l051 (1953)]. Furthermore, the term nickel peroxide is expediently applied to designate the amorphous, black, hydrous and higher oxides of nickel which are formed by the reaction between a strong oxidizing agent such as alkali hypohalites or alkali persulfates and freshly precipitated nickelous hydroxide.

Since telomerization can readily produce a variety of useful polymers which are made of several polymerized "ice molecules of a polymerizable substance and the fragments of only one other molecule depending on a suitable control of polymerization conditions, it has been broadly applied in chemical industry.

Telomerization generally proceeds on a free radical mechanism and is initiated by the action of a radical initiator on a telogen. Further, the degree of polymerization is more or less associated with the employed radical initiator. Accordingly, the selection of a suitable radical initiator is an important key to the successful production of the intended product by telomerization.

There have been heretofore known some radical initiating agents of which examples are as follows: acyl peroxides, alkyl peroxides, salts of per acids, aliphatic azo compounds, tetraalkyl leads, tetraphenyl lead, tetraphenyl tin, dialkyl mercuries, organic magnesium compounds, aluminum chloride, zinc chloride, iron-cobalt, nickel carbony], etc. Of these radical initiating agents, acyl peroxides (e.g. benzoyl peroxide), alkyl peroxides (e.g. ditert-butyl peroxide) and aliphatic azo compounds (e.g. azobisiso-butyronitrile) have been broadly and practically employed because of their good producibility of telomers. However, these practically available initiators each is bound up with disadvantages. For instance, organic peroxides such as acyl peroxides and alkyl peroxides must be carefully treated because they are generally explosive to heat. Further, in general, organic initiators inevitably produce a considerable amount of the by-products of which the molecules contain the fragments of the initiators, the latter being diflicultly eliminated from the reaction product. These and other disadvantages have been now overcome by the present invention. Thus, it has been discovered that nickel peroxide can initiate the radical reaction in telomerization and possesses a number of advantageous properties as follows:

(1) Nickel peroxide is a kind of peroxide but is stable to heat. Accordingly, it can be safely employed in telomerization.

(2) Nickel peroxide is insoluble in any solvent except acids, and the telomerization reaction can proceed in heterogeneous phase, unless the reaction medium is acidic. This makes advantageously possible easy separation of the radical initiator from the reaction mixture by a simple operation.

(3) Nickel peroxide does not produce such unavoidable "Dy-products as produced in the use of organic radical initiators. Accordingly, the recovery of telomers can be readily accomplished.

(4) Nickel peroxide is a black substance and, after the accomplishment of telomerization, changes to inactive nickelous hydroxide which is a green substance. Accordingly, it is possible to know the end point of consumption of the catalyst by the observation of the colourchanging.

(5) Nickel peroxide can be readily prepared by treating an inorganic nickel salt with a strong oxidizing agent such as alkali hypohalites and alkali persulfates, these starting materials being available at low cost. Furthermore, the agent inactivated as the result of the use in telomerization can be easily renewed by a simple procedure, i.e. the treatment with a strong oxidizing agent as stated above. Accordingly, it is an economical radical initiating agent.

(6) Nickel peroxide is an excellent radical initiating agent of as good activity as benzoyl peroxide which has been heretofore the most widely employed. For instance, the yield ratios of 1,1,l-trichloro-3-bromononane in telo- Yield ratio of' l,l,l-trichloro-3-bromononane (percent) Radical ,initiatorz:

(a) Thermal 50 (b) Photochemical 44.5 (c) Acetyl'peroxide' 30 (d) Benzoyl peroxide 35.6 (e) Iron-cobalt powder 83 (f) Nickel carbonyl 40.5 (g) Nickel peroxide -L 9'1 NOTE.The yield ratios were calculated on the basis of the theoretical yield of 1,1,Ltrichloroe3-bromonouane to trichlorobromomethane, The data of (a), (e) and (f) were taken from the report by Miiller et a1. [10. Miiller et al.: Ann, 632, 28

(1960)] and those of (b) and (c) from theaeport by Kharasch sitlgrghglll. S. Kharasch et al.: Am. Chem. $00., 69, 1105 Adding to the above advantageous properties, nickel peroxide characteristically yields a telomer having a relatively low degree of polymerization as the telomerization product by a suitable control of reaction conditions.

firmed. The nickel peroxide possesses usually about 0;3-0.4 *l0- g.-atom of active oxygen per gram (measured by titrating the iodine, produced from the reaction between the nickei peroxide and potassium iodide in acetic acid, with sodium thiosulfate), of which a considerable portion is lost gradually when heated, but remains for a relatively long time when stored at room temperature under protection against light and atmospheric moisture. Generally speaking, the activity as a radical initiator is reduced gradually while in storage and rapidly on heating. Accordingly, the use of freshly produced nickel peroxide' in telomerization is preferred. However, such inactivated nickel peroxide can be readily activated by subjecting the same to the treatment with a strong oxidizing agent as stated above. In this connection, it should be noted that the active nickel peroxide herein described is amorphous, while the commercially available nickel sesquioxide (Ni O is crystalline andinactive, although the latter can be readily activated in the same manner as stated above. The experimental results on the relation between the chemical compositions and the radical initiating activities of a variety of nickel peroxides obtain d depending on the extent of drying and the commercial sesquioxide are shown in the following Table II:

.. a Sample TABLE II n a, b c d W e 3 i Active oxygen (g.-atom/g.) 0. 00390 0. 00384 0. 00321 0. 00400 0. 00150 0 contaminating chlorine (percent) 0. 157 0. 150 Trace 0.170 0. 197 0 contaminating sodium hydroxide i f 7 mg. g.) .s, 0. 628 0. 141 Trace 0. 697 770 0 Nickel (percent) 41. 7 42. 1 42. 3 55.0 60. 8 64. 7 Nickel (corrected) (percent) 65. 62. 8 70. 6 T0. 8 Water (percent) 22. 32 15. 12 4. 60 0 Activity- B8. 7 91. 45. 3 Inactive Inactive- Presumed moiecular formula... NizOa.3HzO 1 Niz a N izO a T1 NoTE.The samplesjfia) and (b) were prepared according to the typical procedure mentioned above and dried at 23 to 25 C. in a desiccator to a constant amount. The sample (c) was prepared and dried in the same manner as in the preparation of the samples (a) and ,(b), but washed with sufliciently more water in the course of the recovery operation than the latter. The samples (d) and (e) were obtained by drying the sample (a) at 80 C. under a pressure of 2 Hg and at 180 C under a pressure of 2mm. Hg, respectively. The sample (i) is a c0m1nercial nickel sesquioxide. The activity is represented bythe theoretical yield ratio oi the telomer (1,1,1-triehl0ro-3-bromononane) to the telogen (trichlorobromomethane) when the telomerization is carried out between Accordingly, a main object of the present invention is to embody nickel peroxide useful as a radical initiator in telomerization. Another object of this invention is to embody nickel peroxide possessing a number of advantages as a radical initiator in telomerization. A further object of the invention is to embody a telomerization process by the use of nickel peroxide as a radical initiator. These and other objects will be apparent to those conversant with the art to which the present invention perrains.

The nickel peroxide employed in the process of the present invention may be prepared by treating a nickel salt (e.g. nickel, chloride, nickel bromide, nickel sulfate, nickel carbonate, nickel nitrate) with a strong oxidizing agent such as alkali hypohalites, (e.g. sodium hypochlorite, potasisurn hypochiorite, sodium hypobromite) or alkali persulfat'e's (e.g. sodium persulfate, potassium persulfate) in an aqueous alkaline mediuin. One of the presently-preferred procedures for obtaining the highly active nickel peroxide is set forth as follows:

To a solution of nickel sulfate hydrate (NiSO .6H O) (136 mg.) in water (300 ml), there is added 'dropwise a solution of sodium hydroxide (42 g.) in 6% sodium hypochlorite, (300 ml.) while stirring, and the resultar t mixture is stirred for about minutes at a temperature between IQ and 25 C. The black precipitate is collected filtration, washed with water to remove active chlorine and, after crushing the cake to powder, dried over anhydrous calcium chloride under reduced pressure.

i The nickel peroxide is a black fine powder containing a considerable amount of water. The results of quantitative analysis make it possible to give the molecular formula: Ni O .3H O(2Ni(=OH) )-Ni O .4H O(Ni O H to the substance, but the structure has not;yet beencontriehlorobromomethane (0.4 mole) and octne-l (1 mole) in the presence of nickel peroxide dontaining 0.10 g. atom of active oxygen at 70 C. {or 4 hours. In the case of the sample (I), 0.1 mole of the same was used.

The probable mechanism of the telomerization according to the process of the present invention is representable by the folowing formulae (wherein nickel peroxide is expediently shown as Ni(OH) 1 OH+Z Initiation. Z'+A ZA' ZA'+(nfl)A Z-(A) Propagation. Z-(A) '+Y-Z Z (A Y+Z' Transfer. Z+Z' ZZ -g Termination.

In these formulae, YrZ is a telogen, Y and Z each being a fragment of the telogen, As the telogen, there may be employed organic or inorganic compounds having a halogen or hydrogen atom which can be abstracted thererirom. More specifically, the present invention involves the use of a lower aliganal (e.g. acetaldehyde,

propionaldehyde, etc.) as the telogen. A hydrogen atom in these telogens is eliminated by the raliical initiator, i.e. nickel peroxide, to leave the free radical designated as 2'. As the taxogen represented by A, there are employed compounds with ethylenic unsaturation, namely, allyl, alcohol, allyl acetate or styrene.

The telomerization may be carried out by reacting a taxogen with a telogen in the presence of nickel peroxide at a suitable temperature. All the reactions in initiation, propagation, transfer and termination can proceed rapidly and successively.

The practical reaction conditions may be decided appropriately, in consideration of the kinds of the telogen and the taxogen, the degree of polymerization of the desired telomer and the like, according to the general knowledge in the field' of telomerization. The nickel peroxide, which is preferred to befreshly produced on use and/or stored under the protection from light, atmospheric moisture and atmospheric oxygen, is usually employed in amounts containing from about 0.010 to about 3.000 g.- atom of active oxygen to one molar amount of the taxogen. A wide range of temperatures, from room temperature to over 250 C., may be adopted for the accomplishment of the telomerization. In fact, the upper temperature limit for telomerization is determined only by the thermal stability of the various compounds in the reacting system. The preferred temperature for any given telomerization depends primarily on the taxogen and the telogen being employed. For the majority of cases, the preferred reaction temperature lies somewhere in the range of 50 to 150 C. As, in ordinary cases, the telogen can perform simultaneously as the reaction medium, no other solvent may be needed. The ratio of telogen to taxogen used in telomerization can be carried widely. In general, increasing the ratio of telogen to taxogen decreases the average molecular weight of the product. The preferred molecular ratio of telogen to taxogen will depend upon the nature of the reactants and the chain length of the product desired, but will generally be in the range of :1 to 1:10. It must be emphasized that the average chain length of the telomer, i.e. the number of taxogen units, is a function of the concentration of taxogen which is maintained in the reaction system. Moreover, the average chain length of the telomer in a given reaction also depends on the nature of the taxogen employed, some taxogens being more active than others. As the atmospheric oxygen acts on the telomerization as an inhibitor, the reaction is normally desired to be executed in an inert gas (e.g. nitrogen, carbon dioxide). The telomerization may be usually executed with or without any regulation of reaction pressure. Generally speaking, the execution of telomerization under a higher pressure aflords a higher average chain of telomer. In all cases, good dispersion is desired and this may be attained simply by shaking or vigorous stirring of the reaction mixture. The process may be aided by the addition of dispersing agents.

The recovery of the telomerization product from the reaction mixture may be carried out by separating the nickel peroxide and treating the resultant in per se conventional manners (e.g. extraction, distillation). The nickel peroxide employed in telomerization can be readily renewed by a simple procedure, i.e. the treatment of the nickel peroxide with a strong oxidizing agent such as alkali hypohalites or alkali persulfates in an aqueous alkaline medium. An example of the presently-preferred renewal procedure is shown as follows:

The collected nickel peroxide is washed with water, stirred with 6% sodium hypochlorite (about ten times the quantity of nickel peroxide) in an aqueous alkaline medium for 20 minutes, filtered, washed with Water and dried.

The obtained allyl alcohol-, allyl acetateand styrenealdehyde reaction products and their uses are known.

The following examplesillustratively set forth presentlypreferred embodiments of the invention.

In these examples, the nickel peroxide is prepared according to the method hereinabove disclosed and, after the measurement of the active oxygen contained therein by iodometry, subjected to telomerization. The yield percent shows the value calculated on the following equation:

Amount of telomer (grams) Amount of taxogen (grams) The molecular formulae of highly polymerized telomers are shown on the basis of the average molecular weight. M.W. means molecular weight.

Yield percent= X 100 stream. Then, the inactivated catalyst is collected by filtration and washed with ether. The washing ether and the filtrate are combined together. The solvent and the unreacted starting materials are evaporated in fresh nitrogen stream. The residue is fractionally distilled to give a compound (1.0 g.) corresponding to the formula:

CHFCHCHOH CHZ=CH HOH (a,OJ-divinyl-ethyleneglycol) as a fraction boiling at 70 to 75 C./ 5 mm. Hg, a compound (5.0 g.) corresponding to the formula: CH COCH CH CH OH ('y-acetopropanol) as a fraction boiling at 83 C./5 mm. Hg and a compound (trace) corresponding to the formula:

as a fraction boiling at a higher temperature than C./3 mm. Hg.

Analysis.-Calcd. for C H O (percent): C, 63.13; H, 8.83; M.W., 114.14. Found (percent): C, 63.73; H, 8.97; M.W., 117.

Analysis.Calcd. for C H O (percent): C, 58.80; H, 9.87; M.W., 102.1. Found (percent): C, 59.24; H, 9.81; M.W., 104.

ArraIysis.Calcd. for C H O (percent): C, 60.52; H, 10.16; M.W., 218.3. Found (percent): C, 60.73; H, 8.97; M.W., 223.

EXAMPLE 2 To a mixture of styrene (0.16 mole) and acetaldehyde (1.6 moles), there is added nickel peroxide containing 0.016 g.-atom of active oxygen, and the resultant mixture is stirred for 40 hours at 20 C. The inactivated catalyst is collected by filtration and added to 30% aqueous acetic acid (200 ml.) containing a small amount of hydroquinone whereby there is precipitated a white substance. The substance is dissolved in benzene, precipitated with methanol, collected by filtration and dried at 60 C. under 5 mm. Hg for 24 hours to give a compound corresponding to the formula: CH CO(C H H as a white powder at 87 to 90 C. in the yield of 31.8%.

Analysis.-Calcd. for C H O (percent): C, 90.56; H, 7.80; M.W., 981.35. Found (percent): C, 90.68; H, 6.92; M.W., 983.0.

EXAMPLE 3 To a mixture of allyl acetate (50.0 g.) and acetaldehyde (88.0 g.), there is added nickel peroxide containing 0.05 g.ato-m of active oxygen, and the resultant mixture is stirred for 35 hours at 20 C. Then, the inactivated catalyst is collected by filtration and washed With ether. The washing ether and the filtrate are combined together, and the unreacted starting materials: and the ether evaporated on a water bath. The residue is dissolved in ether, washed with 5% aqueous sodium hydroxide and water in order, dried over anhydrous sodium sulfate and the solvent removed. The resulting substance is fractionally distilled to give a compound (12.3 g.) corresponding to the formula: CH COCH CH CH OCOCH as a fraction boiling at 53 to 55.5 C./2 mm. Hg and a compound (2.2 g.) corresponding to the formula:

CHQCO CHzCHCHzOH CHsCO as a fraction boiling at to C./l. mm. Hg.

Analysis.Calcd. for C H O (percent): C, 58.31; H, 8.38; M.W., 144.17. Found (percent): C, 58.19; H, 8.79; M.W., 142.

Analysis.Calcd. for C H O (percent): C, 58.05; H, 7.57; M.W., 186. Found (percent): C, 58.19; H, 7.17; M.W., 183.

What is claimed is:

1. A process for the telomerization of a taxogen selected from the group consisting of allyl alcohol, allyl acetate and styrene with a lower alkanal, as telogen,

which comprises reacting the telogen with the taxogen at a molecular ratio of from about 10:1 to about 1:10 in the presence of nickel peroxide at a temperature from ambient temperature to the decomposition temperature of one of the telogen, the taxogen and their addition product, the said nickel peroxide being the product of the treatment of a salt of nickel selected from the group consisting of nickel chloride, nickel bromide, nickel sulfate, nickel carbonate and nickel nitrate with an oxidizing agent selected from the group consisting of alkali hypohalite and alkali persulfate in aqueous alkaline medium at a temperature between 10 and 24 C., said nickel peroxide containing about 0.3 to 0.4 10- gram-atom of active oxygen per gram and being employed in an amount containing from about 0.010 to about 3.000 g.-atom of active oxygen per mole of said taxogen.

2. A process according to claim 1 wherein said taxogen is allyl alcohol.

3. A process according to claim 2, wherein the alkanol is acetaldehyde.

4. A process according to claim 1 wherein said taxogen is allyl acetate.

5. A process according to claim 4, wherein the alkanal is acetaldehyde.

6. A process according to claim 1 wherein said taxogen 1s styrene.

7. A process according to claim 6, wherein the alkanal is acetaldehyde.

References Cited UNITED STATES PATENTS 2,532,287 12/1947 Cramer 260597 2,533,944 12/1950 Ladd 260491 2,552,980 5/1951 Ladd et al. 260-491 3,213,149 10/1965 Takahashi et al. 260-491 3,192,258 6/1965 Nakagawa et al. 260-531 LORRAINE A. WEINBERGER, Primary Examiner V. GARNER, Assistant Examiner US. Cl. X.R. 

